Friday’s "Dateline NBC" episode, airing at 8 p.m., includes new details on the nationwide manhunt to capture Blooming Prairie's Lois Riess. Dubbed “killer grandma,” Riess murdered her husband and fled to Florida, where she killed and stole the identity of Pam Hutchinson, a woman she had just met.

The two-hour episode features the first sit-down interview with Bernie Mathis, whom Riess befriended in Texas just days after killing Hutchinson. Mathis told NBC News’ Dennis Murphy that she was unaware that Riess was on the run for double murder when they met.

“We hit it off like we were going to be best friends,” she said.

RELATED: Lois Riess pleads guilty to husband's murder

After learning of Riess’ arrest and the eerie similarities of how Riess had also befriended Hutchinson just days earlier, Mathis said, “My heart just went in my throat … I just really dodged a bullet.”

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Riess, 58, pleaded guilty to a charge of first-degree murder-premeditated in Dodge County on Aug. 11, 2020. She will spend the rest of her days in a Minnesota prison cell, sentenced to life in prison with no parole.

David Riess was shot and killed on March 11, 2018, after the couple returned home from a grandson’s basketball tournament in Wisconsin. Lois and David had fought on the way home and continued to argue in their bedroom before his death, Lois Riess testified through questioning by her attorney, Lauri Traub.